Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual país tem um PIB (nominal) de $29,9 bilhões?
 ###Tabelas: CREATE TABLE prospective_members (prospective_members_id AUTO_INCREMENT PRIMARY KEY, Country VARCHAR, Population VARCHAR, Area (km²) VARCHAR, GDP (nominal) VARCHAR, GDP per capita (nominal) VARCHAR) CREATE TABLE films_directed_by_tarkovsky (films_directed_by_tarkovsky_id AUTO_INCREMENT PRIMARY KEY, Year INT, English title VARCHAR, Original title VARCHAR, Country VARCHAR, Length VARCHAR) CREATE TABLE michigan_86_ohio_state_0 (michigan_86_ohio_state_0_id AUTO_INCREMENT PRIMARY KEY, Player VARCHAR, Position VARCHAR, Starter VARCHAR, Touchdowns INT, Extra points INT, Field goals INT, Points INT) CREATE TABLE forbes_global_2000 (forbes_global_2000_id AUTO_INCREMENT PRIMARY KEY, April 2013 Cum. Rank INT, Name VARCHAR, Rank 2012 INT, Rank 2013 INT, Base VARCHAR, 2013 rev (bil. USD ) VARCHAR, 2013 Profit (mil. USD ) VARCHAR, Assets 2013 (bil.$) VARCHAR, Market cap March 15 (mil.$) INT) CREATE TABLE former_teams (former_teams_id AUTO_INCREMENT PRIMARY KEY, Team VARCHAR, Sport VARCHAR, League VARCHAR, Established INT, Began in St. Louis INT, Venue VARCHAR, Championships in St. Louis VARCHAR, Left St. Louis INT)  
SELECT Country FROM prospective_members WHERE GDP (nominal) = $29.9 billion